Argument

Focus of this paper is on the historiographical fate of Nicholas Copernicus and Galileo Galilei in Nazi Germany. Both played interesting roles in Nazi propaganda and the legitimization of Nazi political goals. In the “Third Reich,” efforts to claim Copernicus as a German astronomer were closely linked to revisionist policies in Eastern Europe culminating in the war-time expansion. The example of Galileo’s condemnation by the Catholic Church in 1633 became a symbol of its unjustified opposition to new “scientific” results, namely Nazi racial theory. After Catholic opposition against Nazi racial theory had reached a peak in 1937, the Galileo affair was turned into an instrument of Nazi propaganda against the Catholic Church.

Auch der Historiker steht in der Zeit, nicht über ihr.

Das Ewigkeitspostament hat er verloren.

Siegfried Giedion

Argument

Historians have accorded a privileged status to the analytic ideal of elements as a distinctive marker of “modern” chemistry. Boyle’s and Lavoisier’s have been used to characterize their modernity, which has in turn justified their status as the founding fathers of modern chemistry. It has been difficult, however, to establish a viable connection between these two fathers or the genealogy of their definitions. I argue in this paper that French didactic tradition gave rise to the definition Boyle stated in the Sceptical Chymist, or the analytic/philosophical ideal of elements. He did not endorse the definition he gave, but criticized its lack of analytic rigor and philosophical sophistication. His critique served as a negative heuristic, leading to Nicolas Lemery’s analytic ideal of “chemical principles” as distinct from “natural principles.” Lemery’s definition survived in French didactic tradition, as is evidenced in Macquer’s and Guyton’s textbooks which provided direct precedents for Lavoisier’s analytic ideal of “elements or principles.”

Argument

Studies of Helmholtz’s popular lectures on science have concentrated on reconstructing his vision of the scientific enterprise, of its nature, its benefits, and its “civilizing power.” This paper offers a different perspective by focusing on Helmholtz’s attempts to expose his own scientific work to a wider public. Drawing on recent discussions about how to study science popularization, it analyzes how he made his work on sensory physiology accessible to various audiences. It is argued that the exposition of the theory of vision comprises a complex, multilayered transformation of epistemic messages, which includes the recasting of arguments, recontextualizations, shifting emphasis, and significant changes in style. The popular writings on vision were directed to several different audiences, and, as such, manifest a delicate balance between conflicting agendas. An analysis of the texts indicates that neither the traditional two-step model of science popularization nor the more recent attempt to regard popularization as an “expository continuum” provides appropriate historiographical frameworks to study the popularization of scientific knowledge.

Argument

Hermann von Helmholtz’s distinction between “pure intuitive” and “physical” geometry must be counted as the most influential of his many contributions to the philosophy of science. In a series of papers from the 1860s and 70s, Helmholtz argued against Kant’s claim that our knowledge of Euclidean geometry was an a priori condition for empirical knowledge. He claimed that geometrical propositions could be meaningful only if they were taken to concern the behaviors of physical bodies used in measurement, from which it followed that it was posterior to our acquaintance with this behavior. This paper argues that Helmholtz’s understanding of geometry was fundamentally shaped by his work in sense-physiology, above all on the continuum of colors. For in the course of that research, Helmholtz was forced to realize that the color-space had no inherent metrical structure. The latter was a product of axiomatic definitions of color-addition and the empirical results of such additions. Helmholtz’s development of these views is explained with detailed reference to the competing work of the mathematician Hermann Grassmann and that of the young James Clerk Maxwell. It is this separation between 1) essential properties of a continuum, 2) supplementary axioms concerning distance-measurement, and 3) the behaviors of the physical apparatus used to realize the axioms, which is definitive of Helmholtz’s arguments concerning geometry.

Argument

According to Hermann von Helmholtz, free mobility of bodies seemed to be an essential condition of geometry. This free mobility can be interpreted either as matter of fact, as a convention, or as a precondition making measurements in geometry possible. Since Henri Poincaré defined conventions as principles guided by experience, the question arises in which sense experiential data can serve as the basis for the constitution of geometry. Helmholtz considered muscular activity to be the basis on which the form of space could be construed. Yet, due to the problem of illusion inherent in the subject’s self-assessment of muscular activity, this solution yielded new difficulties, in that if the manifold is abstracted from rigid bodies which serve as empirical justification of the geometrical notion of space, then illusionary bodies will produce fictive manifolds. The present article is meant to disentangle these difficulties.

Argument

After having measured the velocity of the nervous impulse in the 1850s, Helmholtz began doing research on the temporal dimensions of visual perception. Experiments dealing with the velocity of propagation in nerves (as well as with aspects of perception) were carried out occasionally for some fifteen years until their final publication in 1871. Although the temporal dimension of perception seems to have interested Helmholtz less than problems of geometry and space, his experiments on the time of perception were technically rather subtle and seminal, especially compared with experiments performed by his contemporaries, such as Sigmund Exner, William James, Rudolf Hermann Lotze, Ernst Mach, Wilhelm Volkmann, and Wilhelm Wundt. Helmholtz’s conception of the temporal aspects of perception reflects the continuity that holds between psychophysiological research and the Kantian philosophical background.